Correlation of virtual network traffic across bare metal servers

ABSTRACT

This disclosure describes techniques that include collecting flow data associated with communications between network devices, and determining, based on the flow data, one or more virtual networks over which the communications are taking place. In one example, this disclosure describes a system configured to perform operations comprising: storing virtual network configuration information associated with a first virtual network and a second virtual network established within a network; collecting underlay flow data associated with communications between a first server and a second server, wherein each of the first server and the second server are implemented as bare metal servers; determining, based on the underlay flow data and the stored virtual network configuration information, that the first server and the second server have communicated over the first virtual network; and generating a user interface.

CROSS REFERENCE

This application is a continuation application of and claims priority to U.S. patent application Ser. No. 16/917,641 filed on Jun. 30, 2020, which is hereby incorporated by reference herein in its entirety.

TECHNICAL FIELD

This disclosure relates to analysis of computer networks, including analyzing paths taken by data through a network.

BACKGROUND

Virtualized data centers are becoming a core foundation of the modern information technology (IT) infrastructure. In particular, modern data centers have extensively utilized virtualized environments in which virtual hosts, such virtual machines or containers, are deployed and executed on an underlying compute platform of physical computing devices.

Virtualization within a large-scale data center can provide several advantages, including efficient use of computing resources and simplification of network configuration. Thus, enterprise IT staff often prefer virtualized compute clusters in data centers for their management advantages in addition to the efficiency and increased return on investment (ROI) that virtualization provides. However, networks in which both virtualized and non-virtualized devices are present can create challenges for analyzing, evaluating, and/or troubleshooting the operation of the network.

SUMMARY

This disclosure describes techniques that include collecting information about physical network infrastructure (e.g., underlay flow data) and network virtualization (e.g., overlay flow data), and correlating the data to enable insights into network operation and performance. In some examples, samples of underlay flow data collected from bare metal devices (e.g., bare metal host devices or servers) are analyzed to determine one or more virtual networks over which communications between such bare metal devices are taking place. In some examples, such analysis may involve using configuration information associated with virtual networks to determine, from the underlay flow data, the virtual network name associated with the virtual network over which one or more bare metal servers are or have communicated.

The techniques described herein may provide one or more technical advantages. For instance, through analysis of flow data, it may be possible to determine, for a given data flow, which tenant the data flow belongs to in a multitenant data center. Further, it may be possible to determine which network devices (including bare metal servers) are source and/or destination devices for such a flow. As described herein, techniques in accordance with one or more aspects of the present disclosure enable identification of virtual networks over which bare metal devices (e.g. host devices or servers) have communicated. Such identification can, in some examples, be determined with little or no overlay flow data. Still further, techniques are described for enriching the underlay flow data with information about overlay data or virtual networks, thereby facilitating analytics that may involve bare metal servers included within a network. By providing information about how the underlay network infrastructure relates to various overlay data flows, creation of useful tools for discovery and investigation is possible. In some examples, such tools may be used for efficient and streamlined troubleshooting and analysis of a network.

In some examples, this disclosure describes operations performed by a network analysis system or other network system in accordance with one or more aspects of this disclosure. In one specific example, this disclosure describes a method comprising storing, by a network analysis system operating within a network, configuration information that includes a name associated with a virtual network; collecting, by the network analysis system, underlay flow data associated with communications between a first server that is physically distinct from a second server; determining, by the network analysis system and based on the underlay flow data and the stored configuration information, that the first server and the second server have communicated over the virtual network; and generating, by the network analysis system, a user interface that includes information indicating that the first server and the second server have communicated over the virtual network.

In another example, this disclosure describes a system including processing circuitry configured to perform operations described herein. In another example, this disclosure describes a non-transitory computer-readable storage medium comprises instructions that, when executed, configure processing circuitry of a computing system to perform operations described herein.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A is a conceptual diagram illustrating an example network that includes a system for analyzing traffic flows across a network and/or within data center, in accordance with one or more aspects of the present disclosure.

FIG. 1B a conceptual diagram illustrating example components of a system for analyzing traffic flows across a network and/or within data center, in accordance with one or more aspects of the present disclosure.

FIG. 2 is a block diagram illustrating an example network for analyzing traffic flows across a network and/or within data center, in accordance with one or more aspects of the present disclosure.

FIG. 3A is a conceptual diagram illustrating an example virtual network data structure associated with a virtual network as maintained by a configuration database, in accordance with one or more aspects of the present disclosure.

FIG. 3B is a conceptual diagram illustrating an example instance of sFlow data, in accordance with one or more aspects of the present disclosure.

FIG. 4 is a conceptual diagram illustrating an example user interface presented by a user interface device in accordance with one or more aspects of the present disclosure.

FIG. 5 is a flow diagram illustrating operations performed by an example network analysis system in accordance with one or more aspects of the present disclosure.

DETAILED DESCRIPTION

Data centers that use virtualized environments in which virtual hosts, such virtual machines or containers are deployed and executed on an underlying compute platform of physical computing devices provide efficiency, cost, and organizational advantages. Yet obtaining meaningful insights into application workloads is nevertheless essential in managing any data center fabric. Collecting traffic samples from networking devices may help provide such insights. In various examples described herein, traffic samples are collected and then processed by analytics algorithms, thereby making it possible to correlate information about overlay traffic with the underlay infrastructure. In some cases, collecting sufficient data from network devices can be a challenge, particularly when such network devices are implemented as bare metal devices or bare metal compute nodes or servers. Techniques are described herein to enable sufficient collection of data in such cases. Further, in some examples, a user interface may be generated to enable visualization of the data collected and how the underlay infrastructure correlates with various overlay networks. Presentation of such data in a user interface may provide insights into the network, and provide users, administrators, and/or other personnel with tools for network discovery, investigation, and troubleshooting.

FIG. 1A is a conceptual diagram illustrating an example network that includes a system for analyzing traffic flows across a network and/or within data center, in accordance with one or more aspects of the present disclosure. FIG. 1A illustrates one example implementation of a network system 100 and a data center 101 that hosts one or more computing networks, computing domains or projects, and/or cloud-based computing networks generally referred to herein as cloud computing cluster. The cloud-based computing clusters and may be co-located in a common overall computing environment, such as a single data center, or distributed across environments, such as across different data centers. Cloud-based computing clusters may, for example, be different cloud environments, such as various combinations of OpenStack cloud environments, Kubernetes cloud environments or other computing clusters, domains, networks and the like. Other implementations of network system 100 and data center 101 may be appropriate in other instances. Such implementations may include a subset of the components included in the example of FIG. 1A and/or may include additional components not shown in FIG. 1A.

In the example of FIG. 1A, data center 101 provides an operating environment for applications and services for customers 104 coupled to data center 101 by service provider network 106. Although functions and operations described in connection with network system 100 of FIG. 1A may be illustrated as being distributed across multiple devices in FIG. 1A, in other examples, the features and techniques attributed to one or more devices in FIG. 1A may be performed internally, by local components of one or more of such devices. Similarly, one or more of such devices may include certain components and perform various techniques that may otherwise be attributed in the description herein to one or more other devices. Further, certain operations, techniques, features, and/or functions may be described in connection with FIG. 1A or otherwise as performed by specific components, devices, and/or modules. In other examples, such operations, techniques, features, and/or functions may be performed by other components, devices, or modules. Accordingly, some operations, techniques, features, and/or functions attributed to one or more components, devices, or modules may be attributed to other components, devices, and/or modules, even if not specifically described herein in such a manner.

Data center 101 hosts infrastructure equipment, such as networking and storage systems, redundant power supplies, and environmental controls. Service provider network 106 may be coupled to one or more networks administered by other providers, and may thus form part of a large-scale public network infrastructure, e.g., the Internet.

In some examples, data center 101 may represent one of many geographically distributed network data centers. As illustrated in the example of FIG. 1A, data center 101 is a facility that provides network services for customers 104. Customers 104 may be collective entities such as enterprises and governments or individuals. For example, a network data center may host web services for several enterprises and end users. Other exemplary services may include data storage, virtual private networks, traffic engineering, file service, data mining, scientific- or super-computing, and so on. In some examples, data center 101 is an individual network server, a network peer, or otherwise.

In the example of FIG. 1A, data center 101 includes a set of storage systems, application servers, compute nodes, or other devices, including network device 110A through network device 110N (collectively “network devices 110,” representing any number of network devices). Devices 110 may be interconnected via high-speed switch fabric 121 provided by one or more tiers of physical network switches and routers. In some examples, devices 110 may be included within fabric 121, but are shown separately for ease of illustration.

Network devices 110 may be any of a number of different types of network devices (core switches, spine network devices, leaf network devices, edge network devices, or other network devices), but in some examples, one or more devices 110 may serve as physical compute nodes of the data center. For example, one or more of devices 110 may be bare metal servers (i.e., not virtualized servers) that provide an operating environment for execution of one or more customer-specific applications or services. Alternatively, or in addition, one or more of devices 110 may provide an operating environment for one or more virtual machines or other virtualized instances, such as containers. In some examples, one or more of devices 110 may be alternatively referred to as a host computing device or, more simply, as a host. A network device 110 may thereby execute one or more virtualized instances, such as virtual machines, containers, or other virtual execution environment for running one or more services, such as virtualized network functions (VNFs).

In general, each of network devices 110 may be any type of device that may operate on a network and which may generate data (e.g. flow data or sFlow data) accessible through telemetry or otherwise, which may include any type of computing device, sensor, camera, node, surveillance device, or other device. Further, some or all of network devices 110 may represent a component of another device, where such a component may generate data collectible through telemetry or otherwise. For example, some or all of network devices 110 may represent physical or virtual network devices, such as switches, routers, hubs, gateways, security devices such as firewalls, intrusion detection, and/or intrusion prevention devices.

Although not specifically shown, switch fabric 121 may include top-of-rack (TOR) switches coupled to a distribution layer of chassis switches, and data center 101 may include one or more non-edge switches, routers, hubs, gateways, security devices such as firewalls, intrusion detection, and/or intrusion prevention devices, servers, computer terminals, laptops, printers, databases, wireless mobile devices such as cellular phones or personal digital assistants, wireless access points, bridges, cable modems, application accelerators, or other network devices. Switch fabric 121 may perform layer 3 routing to route network traffic between data center 101 and customers 104 by service provider network 106. Gateway 108 acts to forward and receive packets between switch fabric 121 and service provider network 106.

Software-Defined Networking (“SDN”) controller 132 provides a logically and in some cases physically centralized controller for facilitating operation of one or more virtual networks within data center 101 in accordance with one or more examples of this disclosure. In some examples, SDN controller 132 operates in response to configuration input received from orchestration engine 130 via northbound application programming interface (API) 131, which in turn may operate in response to configuration input received from an administrator 128 interacting with and/or operating user interface device 129.

User interface device 129 may be implemented as any suitable device for presenting output and/or accepting user input. For instance, user interface device 129 may include a display. User interface device 129 may be a computing system, such as a mobile or non-mobile computing device operated by a user and/or by administrator 128. User interface device 129 may, for example, represent a workstation, a laptop or notebook computer, a desktop computer, a tablet computer, or any other computing device that may be operated by a user and/or present a user interface in accordance with one or more aspects of the present disclosure. In some examples, user interface device 129 may be physically separate from and/or in a different location than controller 201. In such examples, user interface device 129 may communicate with controller 201 over a network or other means of communication. In other examples, user interface device 129 may be a local peripheral of controller 201, or may be integrated into controller 201.

In some examples, orchestration engine 130 manages functions of data center 101 such as compute, storage, networking, and application resources. For example, orchestration engine 130 may create a virtual network for a tenant within data center 101 or across data centers. Orchestration engine 130 may attach virtual machines (VMs) to a tenant's virtual network. Orchestration engine 130 may connect a tenant's virtual network to an external network, e.g. the Internet or a VPN. Orchestration engine 130 may implement a security policy across a group of VMs or to the boundary of a tenant's network. Orchestration engine 130 may deploy a network service (e.g. a load balancer) in a tenant's virtual network.

In some examples, SDN controller 132 manages the network and networking services such load balancing, security, and may allocate resources from devices 110 that serve as host devices to various applications via southbound API 133. That is, southbound API 133 represents a set of communication protocols utilized by SDN controller 132 to make the actual state of the network equal to the desired state as specified by orchestration engine 130. For example, SDN controller 132 may implement high-level requests from orchestration engine 130 by configuring physical switches, e.g. TOR switches, chassis switches, and switch fabric 121; physical routers; physical service nodes such as firewalls and load balancers; and virtual services such as virtual firewalls in a VM. SDN controller 132 maintains routing, networking, and configuration information within a state database.

Network analysis system 140 interacts with or receives data from one or more of devices 110 (and/or other devices) to collect flow data across data center 101 and/or network system 100. Such flow data may include underlay flow data and overlay flow data. In some examples, the underlay flow data may be collected through samples of flow data collected at Layer 2 of the OSI model. Overlay flow data may be data (e.g., samples of data) derived from overlay traffic across one or more virtual networks established within network system 100. Overlay flow data may, for example, include information identifying a source virtual network and a destination virtual network.

In accordance with one or more aspects of the present disclosure, network analysis system 140 of FIG. 1A may configure each of devices 110 to collect flow data. For instance, in an example that can be described with reference to FIG. 1A, network analysis system 140 outputs a signal to each of devices 110. Each of devices 110 receives a signal and interprets the signal as a command to collect flow data, including underlay flow data and/or overlay flow data. Thereafter, each of devices 110 communicates underlay flow data and/or overlay flow data to network analysis system 140 as data packets are processed by each of devices 110. Network analysis system 140 receives the flow data, prepares it for use in response to analytical queries, and stores the flow data. In the example of FIG. 1A, other network devices, including network devices within switch fabric 121 (and not specifically shown), may also be configured to collect underlay and/or overlay flow data.

In some examples, one or more of devices 110 may be or may operate as a bare metal server (e.g., a non-virtualized host compute node). In such an example, such a bare metal server device 110 might collect underlay flow data (e.g., “sFlow” data), but might collected little or no overlay flow data. In some examples, a compute node or host that is a bare metal server might not have one or more software components (e.g., a virtual router) that are necessary for the collection of overlay flow data. In such an example, a bare metal server device might collect underlay flow data, but no overlay flow data.

Network analysis system 140 may process a query. For instance, in the example being described, user interface device 129 detects input and outputs information about the input to network analysis system 140. Network analysis system 140 determines that the information corresponds to a request for information about network system 100 from a user of user interface device 129. Network analysis system 140 processes the request by querying stored flow data. Network analysis system 140 generates a response to the query based on the stored flow data, and outputs information about the response to user interface device 129.

In some examples, the request received from user interface device 129 may include a source and/or destination virtual network. In such an example, the network analysis system 140 may, in response to such a request, identify one or more likely data paths over underlay network devices that packets traveling from the source virtual network to the destination virtual network may have taken. To identify the likely data paths, network analysis system 140 may correlate the collected overlay flow data with the collected underlay flow data so that the underlay network devices used by an overlay data flow can be identified.

FIG. 1B a conceptual diagram illustrating example components of a system for analyzing traffic flows across a network and/or within data center, in accordance with one or more aspects of the present disclosure. FIG. 1B includes many of the same elements described in connection with FIG. 1A. Elements illustrated in FIG. 1B may correspond to elements illustrated in FIG. 1A that are identified by like-numbered reference numerals in FIG. 1A. In general, such like-numbered elements may be implemented in a manner consistent with the description of the corresponding element provided in connection with FIG. 1A, although in some examples, such elements may involve alternative implementation with more, fewer, and/or different capabilities and attributes.

Unlike FIG. 1A, however, FIG. 1B illustrates components of network analysis system 140. Network analysis system 140 is shown as including load balancer 141, flow collector 142, queue & event store 143, topology & metrics source 144, data store 145 and flow API 146. In general, network analysis system 140 and components of network analysis system 140 are designed and/or configured to ensure high availability and an ability to process a high volume of flow data. In some examples, multiple instances of components of network analysis system 140 may be orchestrated (e.g., by orchestration engine 130) to execute on different physical servers to ensure that there is no single point of failure for any component of network analysis system 140. In some examples, network analysis system 140 or components thereof may be scaled independently and horizontally to enable efficient and/or effective processing of a desired volume of traffic (e.g., flow data).

Network analysis system 140 of FIG. 1B may, as in FIG. 1A, configure each of devices 110 to collect flow data. For instance, network analysis system 140 may output a signal to each of devices 110 to configure each of devices 110 to collect flow data, including underlay flow data and overlay flow data. One or more of devices 110 may thereafter collect underlay flow data and/or overlay flow data and report such flow data to network analysis system 140.

In FIG. 1B, receiving the flow data from each of devices 110 is performed by load balancer 141 of network analysis system 140. For instance, in FIG. 1B, load balancer 141 may receive the flow data from each of devices 110. Load balancer 141 may distribute the traffic across multiple flow collectors to ensure an active/active failover strategy for the flow collectors. In some examples, multiple load balancers 141 may be required to ensure high availability and scalability.

Flow collector 142 collects data from load balancer 141. For example, flow collector 142 of network analysis system 140 receives and processes flow packets from each of devices 110 (after processing by load balancer 141). Flow collector 142 sends the flow packets upstream to queue & event store 143. In some examples, flow collector 142 may address, process, and/or accommodate unified data from sFlows, NetFlow v9, IPFIX, jFlow, Contrail Flow, and other formats. Flow collector 142 may be capable of parsing the inner header from sFlow packets and other data flow packets. Flow collector 142 may be able to handle message overflows and enriched flow records with topology information (e.g., AppFormix topology information). Flow collector 142 may also be able to covert data to binary format before writing or sending data to queue & event store 143. Underlay flow data of the “sFlow” type, which refers to a “sampled flow,” is a standard for packet export at Layer 2 of the OSI model. It provides a means for exporting truncated packets, together with interface counters for the purpose of network monitoring.

Queue & event store 143 processes the collected data. For example, queue & event store 143 may receive data from one or more flow collectors 142, store the data, and make the data available for ingestion in data store 145. In some examples, this enables separation of the task of receiving and storing large volumes of data from the task of indexing the data and preparing it for analytical queries. In some examples, queue & event store 143 may also enable independent users to directly consume the stream of flow records. In some examples, queue & event store 143 may be used to discover anomalies and produce alerts in near-real time or seemingly near real time. In some examples, flow data may be parsed by reading encapsulated packets, including VXLAN, MPLS over UDP, and MPLS over GRE. From the inner (underlay) packet, queue & event store 143 parses the source IP, destination IP, source port, destination port, and protocol. Some types of flow data (including sFlow data) include only a fragment of sampled network traffic (e.g., the first 128 bytes), so in some cases, the flow data might not include all of the inner fields. In such an example, such data may be marked as missing.

Topology & metrics source 144 may enrich or augment the data with topology information and/or metrics information. For example, topology & metrics source 144 may provide network topology metadata, which may include identified nodes or network devices, configuration information, configuration, established links, and other information about such nodes and/or network devices. In some examples, topology & metrics source 144 may use AppFormix topology data or may be an executing AppFormix module. The information received from topology & metrics source 144 may be used to enrich flow data collected by flow collector 142 and support flow API 146 in processing queries of data store 145.

Data store 145 may be configured to store data received from queue & event store 143 and topology & metrics source 144 in an indexed format, enabling fast aggregation queries and fast random-access data retrieval. In some examples, data store 145 may achieve fault tolerance and high availability by sharding and replicating the data.

Flow API 146 may process query requests sent by one or more user interface devices 129. For instance, in some examples, flow API 146 may receive a query request from user interface device 129 through an HTTP POST request. In such an example, flow API 146 converts information included within the request to a query for data store 145. To create the query, flow API 146 may use topology information from topology & metrics source 144. Flow API 146 may use one or more of such queries to perform analytics on behalf of user interface device 129. Such analytics may include traffic deduplication, overlay-underlay correlation, traffic path identification, and/or heatmap traffic calculation. In particular, such analytics may involve correlating the underlay flow data with the overlay flow data, thereby enabling identification of which underlay network devices are relevant to traffic flowing over a virtual network and/or between two virtual machines.

Through techniques in accordance with one or more aspects of the present disclosure, such as by correlating underlay flow data with overlay flow data, network analysis system 140 may be able to determine, for a given data flow, which tenant the data flow belongs to in a multitenant data center. Further, network analysis system 140 may also be able to determine which virtual computing instances (e.g., virtual machines or containers) are source and/or destination virtual computing instances for such a flow. As described herein, techniques in accordance with one or more aspects of the present disclosure enable identification of virtual networks over which bare metal devices (e.g. host devices or servers) have communicated. Such identification can be advantageously determined with little or no overlay flow data. Still further, techniques are described for enriching the underlay flow data with information about overlay data or virtual networks, thereby facilitating analytics that may involve bare metal servers included within a network.

FIG. 2 is a block diagram illustrating an example network for analyzing traffic flows across a network and/or within data center, in accordance with one or more aspects of the present disclosure. Network system 200 of FIG. 2 may be described as an example or alternative implementation of network system 100 of FIG. 1A or FIG. 1B. One or more aspects of FIG. 2 may be described herein within the context of FIG. 1.

Although a data center, such as that illustrated in FIG. 1A, FIG. 1B, and FIG. 2 may be operated by any entity, some data centers are operated by a service provider, where the business model of such a service provider may involve providing computing capacity to customers or clients. For this reason, data centers usually contain a huge number of compute nodes, or host devices. In order to operate efficiently, those hosts have to be connected to each other and to the external world, and that ability is provided through physical network devices, which may be interconnected in a leaf-spine topology. The collection of these physical devices, such as network devices and hosts, form the underlay network.

Each host device in such a data center usually has several virtual machines running on it, which are called workloads. Clients of the data center usually have access to these workloads, and can install applications and perform other operations using such workloads. Workloads that run on different host devices but are accessible by one particular client are organized into a virtual network. Each client usually has at least one virtual network. Those virtual networks are also called overlay networks. In some cases, a client of the data center may experience connectivity issues between two applications that are running on different workloads. Troubleshooting such issues tends to be complicated by the deployment of the workloads in a large multitenant data center. In addition, performing analytics for a specific virtual network or a specific client or tenant also tends to be complicated by deployment of the workloads in a large multitenant data center.

In the example of FIG. 2, network 205 connects network analysis system 240, host device 210A, host device 210B, and host device 210N. Network analysis system 240 may correspond to an example or alternative implementation of network analysis system 140 illustrated in FIG. 1A and FIG. 1B. Host devices 210A, 210B, through 210N may be collectively referenced as “host devices 210,” representing any number of host devices 210.

Each of host devices 210 may be an example of devices 110 of FIG. 1A and FIG. 1B, but in the example of FIG. 2, each of host devices 210 is implemented as a server or host device that operates as a physical or virtualized compute node of a virtualized data center, as opposed to a network device. As further described herein, one or more of host devices 210 (e.g., host device 210A of FIG. 2) may execute multiple virtual computing instances, such as virtual machines 228, and in addition, one or more of host devices 210 (e.g., one or more of host devices 210B through 210N) may execute applications or service modules 277 on a non-virtualized, single-tenant, and/or bare metal server. Accordingly, as in FIG. 1A and FIG. 1B, the example of FIG. 2 illustrates a network system that includes a mix of virtualized server devices and bare metal server devices.

Also connected to network 205 is user interface device 129, which may be operated by administrator 128, as in FIG. 1A and FIG. 1B. In some examples, user interface device 129 may present, at a display device associated with user interface device 129, one or more user interfaces, some of which may have a form similar to user interface 400.

FIG. 2 also illustrates underlay flow data 204 and overlay flow data 206 flowing within network system 200. In particular, underlay flow data 204 is shown leaving spine device 202A and flowing to network analysis system 240. Similarly, overlay flow data 206 is shown leaving host device 210A and flowing across 205. In some examples, overlay flow data 206 is communicated through network 205 and to network analysis system 240 as described herein. For simplicity, FIG. 2 illustrates a single instance of underlay flow data 204 and a single instance of overlay flow data 206. However, it should be understood that each of spine devices 202 and leaf devices 203 may generate and communicate underlay flow data 204 to network analysis system 240, and in some examples, each of host devices 210 (and/or other devices) may generate underlay flow data 204 and communicate such data across network 205 to network analysis system 240. Further, it should be understood that one or more of host devices 210 (and/or other devices) may generate overlay flow data 206 and communicate such data over network 205 to network analysis system 240. In some examples, however, one or more of host devices 210 may be implemented as a bare metal server or single-tenant server that does not generate overlay flow data 206. In the example of FIG. 2, host device 210B and host device 210N may be implemented as bare metal servers.

Network 205 may correspond to any of switch fabric 121 and/or service provider network 106 of FIG. 1A and FIG. 1B, or alternatively, may correspond to a combination of switch fabric 121, service provider network 106, and/or another network. Network 205 may also include some of the components of FIG. 1A and FIG. 1B, including gateway 108, SDN controller 132, and orchestration engine 130.

Illustrated within network 205 are spine devices 202A and 202B (collectively “spine devices 202” and representing any number of spine devices 202), as well as leaf device 203A, 203B, and leaf device 203C (collectively “leaf devices 203” and also representing any number of leaf devices 203). Although network 205 is illustrated with spine devices 202 and leaf devices 203, other types of network devices may be included in network 205, including core switches, edge network devices, top-of-rack devices, and other network devices.

In general, network 205 may be the internet, or may include or represent any public or private communications network or other network. For instance, network 205 may be a cellular, Wi-Fi®, ZigBee, Bluetooth, Near-Field Communication (NFC), satellite, enterprise, service provider, and/or other type of network enabling transfer of transmitting data between computing systems, servers, and computing devices. One or more of client devices, server devices, or other devices may transmit and receive data, commands, control signals, and/or other information across network 205 using any suitable communication techniques. Network 205 may include one or more network hubs, network switches, network routers, satellite dishes, or any other network equipment. Such devices or components may be operatively inter-coupled, thereby providing for the exchange of information between computers, devices, or other components (e.g., between one or more client devices or systems and one or more server devices or systems). Each of the devices or systems illustrated in FIG. 2 may be operatively coupled to network 205 using one or more network links. The links coupling such devices or systems to network 205 may be Ethernet, Asynchronous Transfer Mode (ATM) or other types of network connections, and such connections may be wireless and/or wired connections. One or more of the devices or systems illustrated in FIG. 2 or otherwise on network 205 may be in a remote location relative to one or more other illustrated devices or systems.

Network analysis system 240 may be implemented as any suitable computing system, such as one or more server computers, workstations, mainframes, appliances, cloud computing systems, and/or other computing systems that may be capable of performing operations and/or functions described in accordance with one or more aspects of the present disclosure. In some examples, network analysis system 240 represents a cloud computing system, server farm, and/or server cluster (or portion thereof) that provides services to client devices and other devices or systems. In other examples, network analysis system 240 may represent or be implemented through one or more virtualized compute instances (e.g., virtual machines, containers) of a data center, cloud computing system, server farm, and/or server cluster.

In the example of FIG. 2, network analysis system 240 may include power source 241, one or more processors 243, one or more communication units 245, one or more input devices 246, and one or more output devices 247. Storage devices 250 may include one or more collector modules 252, user interface module 254, flow API 256, and data store 259.

One or more of the devices, modules, storage areas, or other components of network analysis system 240 may be interconnected to enable inter-component communications (physically, communicatively, and/or operatively). In some examples, such connectivity may be provided by through communication channels (e.g., communication channels 242), a system bus, a network connection, an inter-process communication data structure, or any other method for communicating data.

Power source 241 may provide power to one or more components of network analysis system 240. Power source 241 may receive power from the primary alternating current (AC) power supply in a data center, building, home, or other location. In other examples, power source 241 may be a battery or a device that supplies direct current (DC). In still further examples, network analysis system 240 and/or power source 241 may receive power from another source. One or more of the devices or components illustrated within network analysis system 240 may be connected to power source 241, and/or may receive power from power source 241. Power source 241 may have intelligent power management or consumption capabilities, and such features may be controlled, accessed, or adjusted by one or more modules of network analysis system 240 and/or by one or more processors 243 to intelligently consume, allocate, supply, or otherwise manage power.

One or more processors 243 of network analysis system 240 may implement functionality and/or execute instructions associated with network analysis system 240 or associated with one or more modules illustrated herein and/or described herein. One or more processors 243 may be, may be part of, and/or may include processing circuitry that performs operations in accordance with one or more aspects of the present disclosure. Examples of processors 243 include microprocessors, application processors, display controllers, auxiliary processors, one or more sensor hubs, and any other hardware configured to function as a processor, a processing unit, or a processing device. Central monitoring system 210 may use one or more processors 243 to perform operations in accordance with one or more aspects of the present disclosure using software, hardware, firmware, or a mixture of hardware, software, and firmware residing in and/or executing at network analysis system 240.

One or more communication units 245 of network analysis system 240 may communicate with devices external to network analysis system 240 by transmitting and/or receiving data, and may operate, in some respects, as both an input device and an output device. In some examples, communication unit 245 may communicate with other devices over a network. In other examples, communication units 245 may send and/or receive radio signals on a radio network such as a cellular radio network. Examples of communication units 245 include a network interface card (e.g. such as an Ethernet card), an optical transceiver, a radio frequency transceiver, a GPS receiver, or any other type of device that can send and/or receive information. Other examples of communication units 245 may include devices capable of communicating over Bluetooth®, GPS, NFC, ZigBee, and cellular networks (e.g., 3G, 4G, 5G), and Wi-Fi® radios found in mobile devices as well as Universal Serial Bus (USB) controllers and the like. Such communications may adhere to, implement, or abide by appropriate protocols, including Transmission Control Protocol/Internet Protocol (TCP/IP), Ethernet, Bluetooth, NFC, or other technologies or protocols.

One or more input devices 246 may represent any input devices of network analysis system 240 not otherwise separately described herein. One or more input devices 246 may generate, receive, and/or process input from any type of device capable of detecting input from a human or machine. For example, one or more input devices 246 may generate, receive, and/or process input in the form of electrical, physical, audio, image, and/or visual input (e.g., peripheral device, keyboard, microphone, camera).

One or more output devices 247 may represent any output devices of network analysis system 240 not otherwise separately described herein. One or more output devices 247 may generate, receive, and/or process input from any type of device capable of detecting input from a human or machine. For example, one or more output devices 247 may generate, receive, and/or process output in the form of electrical and/or physical output (e.g., peripheral device, actuator).

One or more storage devices 250 within network analysis system 240 may store information for processing during operation of network analysis system 240. Storage devices 250 may store program instructions and/or data associated with one or more of the modules described in accordance with one or more aspects of this disclosure. One or more processors 243 and one or more storage devices 250 may provide an operating environment or platform for such modules, which may be implemented as software, but may in some examples include any combination of hardware, firmware, and software. One or more processors 243 may execute instructions and one or more storage devices 250 may store instructions and/or data of one or more modules. The combination of processors 243 and storage devices 250 may retrieve, store, and/or execute the instructions and/or data of one or more applications, modules, or software. Processors 243 and/or storage devices 250 may also be operably coupled to one or more other software and/or hardware components, including, but not limited to, one or more of the components of network analysis system 240 and/or one or more devices or systems illustrated as being connected to network analysis system 240.

In some examples, one or more storage devices 250 are implemented through temporary memory, which may mean that a primary purpose of the one or more storage devices is not long-term storage. Storage devices 250 of network analysis system 240 may be configured for short-term storage of information as volatile memory and therefore not retain stored contents if deactivated. Examples of volatile memories include random access memories (RAM), dynamic random access memories (DRAM), static random access memories (SRAM), and other forms of volatile memories known in the art. Storage devices 250, in some examples, also include one or more computer-readable storage media. Storage devices 250 may be configured to store larger amounts of information than volatile memory. Storage devices 250 may further be configured for long-term storage of information as non-volatile memory space and retain information after activate/off cycles. Examples of non-volatile memories include magnetic hard disks, optical discs, Flash memories, or forms of electrically programmable memories (EPROM) or electrically erasable and programmable (EEPROM) memories.

Collector module 252 may perform functions relating to receiving both underlay flow data 204 and overlay flow data 206, and performing load balancing as necessary to ensure high availability, throughput, and scalability for collecting such flow data. Collector module 252 may process the data prepare the data for storage within data store 259. In some examples, collector module 252 may store the data within data store 259.

User interface module 254 may perform functions relating to generating user interfaces for presenting the results of analytical queries performed by flow API 256. In some examples, user interface module 254 may generate information sufficient to generate a set of user interfaces, and cause communication unit 215 to output such information over network 205 for use by user interface device 129 to present one or more user interfaces at a display device associated with user interface device 129.

Flow API 256 may perform analytical queries involving data stored in data store 259 that is derived from collection of underlay flow data 204 and overlay flow data 206. In some examples, flow API 256 may receive a request in the form of information derived from an HTTP POST request, and in response, may convert the request into a query to be executed on data store 259. Further, in some examples, flow API 256 may fetch topology information pertaining to the device 110, and perform analytics that include data deduplication, overlay-underlay correlation, traffic path identification, and heatmap traffic calculation.

Data store 259 may represent any suitable data structure or storage medium for storing information related to data flow information, including storage of data derived from underlay flow data 204 and overlay flow data 206. Data store 259 may be responsible for storing data in an indexed format, enabling fast data retrieval and execution of queries. The information stored in data store 259 may be searchable and/or categorized such that one or more modules within network analysis system 240 may provide an input requesting information from data store 259, and in response to the input, receive information stored within data store 259. Data store 259 may be primarily maintained by collector module 252. Data store 259 may include configuration information enabling identification of a virtual network based only on a virtual network identifier, or a coded reference to a virtual network. In some examples, the information stored within data store 259 may correspond to or include a Contrail Configuration Database associated with the Contrail cloud network automation solutions from Juniper Networks of Sunnyvale, Calif. Data store 259 may be implemented through multiple hardware devices, and may achieve fault tolerance and high availability by sharding and replicating data. In some examples, data store 259 may be implemented using the open source ClickHouse column-oriented database management system. In some examples, data store 259 may achieve fault tolerance and high availability by sharding and replicating the data across multiple storage devices, which may be located across multiple physical hosts.

Each of host devices 210 represents a physical computing device or compute node that provides an execution environment for virtual hosts, virtual machines, containers, and/or other virtualized computing resources. In some examples, each of host devices 210 may be a component of a cloud computing system, server farm, and/or server cluster (or portion thereof) that provides services to client devices and other devices or systems.

Certain aspects of host devices 210 are described herein with respect to host device 210A. Other host devices 210 (e.g., host device 210B through 210N) may be described similarly, and may also include like-numbered components that may represent the same, similar, or corresponding components, devices, modules, functionality, and/or other features. Descriptions herein with respect to host device 210A may therefore correspondingly apply to one or more other host devices 210 (e.g., host device 210B through host device 210N).

In the example of FIG. 2, host device 210A includes underlying physical compute hardware that includes power source 211A, one or more processors 213A, one or more communication units 215A, one or more input devices 216A, one or more output devices 217A, and one or more storage devices 220A. In the example shown, storage devices 220A may include hypervisor module 221A, which may include kernel module 222, virtual router module 224, and agent module 226. Virtual machines 228A through 228N (collectively “virtual machines 228” and representing any number of virtual machines 228) execute on top of hypervisor 221A or are controlled by hypervisor 221A. Similarly, virtual router agent 229A may execute on, or under the control of, hypervisor 221A. One or more of the devices, modules, storage areas, or other components of host device 210A may be interconnected to enable inter-component communications (physically, communicatively, and/or operatively). In some examples, such connectivity may be provided by through communication channels (e.g., communication channels 212A), a system bus, a network connection, an inter-process communication data structure, or any other method for communicating data.

Power source 211A may provide power to one or more components of host device 210A. Processor 213A may implement functionality and/or execute instructions associated with host device 210A. Communication unit 215A may communicate with other devices or systems on behalf of host device 210A. One or more input devices 216A and output devices 217A may represent input and/or output devices associated with host device 210A. Storage devices 220A may store information for processing during operation of host device 210A. Each of such components may be implemented in a manner similar to those described herein in connection with network analysis system 240 or otherwise.

Hypervisor 221A may serve as a module or system that instantiates, creates, and/or executes one or more virtual machines 228 on an underlying host hardware device. In some contexts, hypervisor 221A may be referred to as a virtual machine manager (VMM). Hypervisor 221A may execute within the execution environment provided by storage devices 220A and processors 213A or on top of an operating system kernel (e.g., kernel module 222A). In some examples, hypervisor 221A is an operating system-level component that executes on a hardware platform (e.g., host 210A) to provide a virtualized operating environment and orchestration controller for virtual machines 228A, and/or other types of virtual computing instances. In other examples, hypervisor 221A may be a software and/or firmware layer that provides a lightweight kernel and operates to provide a virtualized operating environment and orchestration controller for virtual machines 228A, and/or other types of virtual computing instances. Hypervisor 221A may incorporate the functionality of kernel module 222A (e.g., as a “type 1 hypervisor”), as shown in FIG. 2. In other examples, hypervisor 221A may execute on a kernel (e.g., as a “type 2 hypervisor”).

Virtual router module 224A may execute multiple routing instances for corresponding virtual networks within data center 101 (see FIG. 1) and may route packets to appropriate virtual machines executing within the operating environment provided by host device 110A. Virtual router module 224A may also be responsible for collecting overlay flow data, such as Contrail Flow data when used in an infrastructure in which the Contrail SDN is employed. Accordingly, one or more of host devices 210 may include a virtual router. Packets received by virtual router module 224A of host device 210A, for instance, from the underlying physical network fabric may include an outer header to allow the physical network fabric to tunnel the payload or “inner packet” to a physical network address for a network interface of host device 210A. The outer header may include not only the physical network address of the network interface of the server but also a virtual network identifier such as a VxLAN tag or Multiprotocol Label Switching (MPLS) label that identifies one of the virtual networks as well as the corresponding routing instance executed by the virtual router. An inner packet includes an inner header having a destination network address that conform to the virtual network addressing space for the virtual network identified by the virtual network identifier.

Agent module 226A may execute as part of hypervisor 221A, or may execute within kernel space or as part of kernel module 222A. Agent module 226A may monitor some or all of the performance metrics associated with host device 210A, and may implement and/or enforcing policies, which may be received from a policy controller (not shown in FIG. 2). Agent module 226A may configure virtual router module 224A to communicate overlay flow data to network analysis system 240.

Virtual machine 228A through virtual machine 228N (collectively “virtual machines 228,” representing any number of virtual machines 228) may represent example instances of virtual machines 228. Host device 210A may partition the virtual and/or physical address space provided by storage device 220A into user space for running user processes. Host device 210A may also partition virtual and/or physical address space provided by storage device 220A into kernel space, which is protected and may be inaccessible by user processes.

In general, each of virtual machines 228 may be any type of software application and each may be assigned a virtual address for use within a corresponding virtual network, where each of the virtual networks may be a different virtual subnet provided by virtual router module 224A. Each of virtual machines 228 may be assigned its own virtual layer three (L3) IP address, for example, for sending and receiving communications but is unaware of an IP address of the physical server on which the virtual machine is executing. In this way, a “virtual address” is an address for an application that differs from the logical address for the underlying, physical computer system, e.g., host device 210A in the example of FIG. 2.

Each of virtual machines 228 may represent a tenant virtual machine running customer applications such as Web servers, database servers, enterprise applications, or hosting virtualized services used to create service chains. In some cases, any one or more of host devices 210 or another computing device hosts customer applications directly, i.e., not as virtual machines (e.g., one or more of host devices 210B through 210N, such as host device 210B and host device 210N). Although one or more aspects of the present disclosure are described in terms of virtual machines or virtual hosts, techniques in accordance with one or more aspects of the present disclosure that are described herein with respect to such virtual machines or virtual hosts may also apply to containers, applications, processes, or other units of execution (virtualized or non-virtualized) executing on host devices 210.

Virtual router agent 229A is included within host device 210A in the example of FIG. 2 and may communicate with SDN controller 132 (see FIGS. 1A and 1B) and virtual router module 224A so as to control the overlay of virtual networks and coordinate the routing of data packets within host device 210A. In general, virtual router agent 229A communicates with SDN controller 132, which generates commands to control routing of packets through data center 101. Virtual router agent 229A may execute in user space and operate as a proxy for control plane messages between virtual machines 228 and SDN controller 132. For example, virtual machine 228A may request to send a message using its virtual address via virtual router agent 229A, and virtual router agent 229A may in turn send the message and request that a response to the message be received for the virtual address of virtual machine 228A, which originated the first message. In some cases, virtual machine 228A may invoke a procedure or function call presented by an application programming interface of virtual router agent 229A, and in such an example, virtual router agent 229A handles encapsulation of the message as well, including addressing.

In the example of FIG. 2, host device 210B includes, like host device 210A, underlying physical compute hardware that includes power source 2111B, one or more processors 213B, one or more communication units 215B, one or more input devices 216B, one or more output devices 217B, and one or more storage devices 220B. Storage devices 220B may include one or more application modules 231B, which may correspond to applications executing by or on behalf of one or more tenants of host device 210B. In the example of FIG. 2, host device 210B may be a bare metal server, which may mean that host device 210B executes as a single tenant device without virtualized components as in, for example, host device 210A. In such an example, host device 210B might not include any component or module that corresponds to virtual router module 224A, agent module 226A, and/or virtual router agent 229A of host device 210A. Without any such components or modules, host device 210B may be able to report underlay flow data 204, but might not be able to report overlay flow data 206, particularly where a virtual router agent typically performs the function of reporting overlay flow data 206.

Host devices 210 may be implemented as either a virtualized compute node (e.g., as in host device 210A), as a bare metal server (e.g., as in host device 210B), or in another way. As illustrated in FIG. 2, host device 210N is shown implemented as a bare metal server, similar to that of host device 210B. Accordingly, host device 210N is shown having like-numbered elements that correspond to those of host device 210B, and which may be implemented in a similar manner.

Network analysis system 240 may configure each of spine devices 202 and leaf devices 203 to collect underlay flow data 204. For instance, in an example that can be described with reference to FIG. 2, collector module 252 of network analysis system 240 causes communication unit 245 to output one or more signals over network 205. Each of spine devices 202 and leaf devices 203 detect a signal and interpret the signal as a command to enable collection of underlay flow data 204. For example, upon detecting a signal from network analysis system 240, spine device 202A configures itself to collect sFlow data and communicate the sFlow data (as underlay flow data 204) over network 205 to network analysis system 240. As another example, upon detecting a signal from network analysis system 240, leaf device 203A detects a signal and configures itself to collect sFlow data and communicate the sFlow data over network 205 to network analysis system 240. Further, in some examples, each of host devices 210 may detect a signal from network analysis system 240, and interpret the signal as a command to enable collection of sFlow data. Thus, in some examples, sFlow data may be collected by collector modules executing on host devices 210.

Accordingly, in the example being described, spine devices 202, leaf devices 203 (and possibly one or more or all of host devices 210) collect sFlow data. In other examples, however, one or more of such devices may collect other types of underlay flow data 204, such as IPFIX and/or NetFlow data. Collecting any such underlay flow data may involve collection of a five-tuple of data that includes the source and destination IP address, the source and destination port number, and the network protocol being used.

Network analysis system 240 may configure one or more of host devices 210 to collect overlay flow data 206. For instance, continuing with the example being described with reference to FIG. 2, collector module 252 causes communication unit 245 to output one or more signals over network 205. One or more of host devices 210 detect a signal that is interpreted as a command to collect overlay flow data 206 and communicate overlay flow data 206 to network analysis system 240.

For example, with reference to host device 210A, communication unit 215A of host device 210A detects a signal over network 205 and outputs information about the signal to hypervisor 221A. Hypervisor 221A outputs information to agent module 226A. Agent module 226A interprets the information from hypervisor 221A as a command to collect overlay flow data 206. Agent module 226A configures virtual router module 224A to collect overlay flow data 206 and communicate overlay flow data 206 to network analysis system 240. Host devices 210 implemented as bare metal servers, however, might not detect or respond to a signal over network 205 to collect overlay flow data 206. For systems in which host devices 210 rely on a virtual router or virtual router agent corresponding to virtual router module 224A or agent module 226A to generate, collect, and/or report overlay flow data, overlay flow data for host devices 210 implemented as bare metal servers might not be received by network analysis system 240.

Overlay flow data 206 collected by host device 210A includes, in at least some examples, the five-tuple of information about the source and destination addresses, ports, and protocol. In addition, overlay flow data 206 may include information about the virtual networks associated with the flow, including the source virtual network and the destination virtual network. In some examples, particularly for a network configured using the Contrail SDN available from Juniper Networks of Sunnyvale, Calif., overlay flow data 206 may correspond to Contrail Flow data.

In the example being described, agent module 226A configures virtual router module 224A of host device 210A to collect overlay flow data 206. In other examples, however, hypervisor 221A may configure virtual router module 224A to collect overlay flow data 206. Further, in other examples, overlay flow data 206 data may be collected by another module (alternatively or in addition), such as agent module 226A or even by hypervisor 221A or kernel module 222A. Accordingly, one or more of host devices 210 may collect both underlay flow data (sFlow data) and overlay flow data (e.g., Contrail Flow data) in various ways.

Network analysis system 240 may receive both underlay flow data 204 and overlay flow data 206. For instance, continuing with the example and with reference to FIG. 2, spine device 202A samples, detects, senses, and/or collects underlay flow data 204. Spine device 202A outputs a signal over network 205. Communication unit 245 of network analysis system 240 detects a signal from spine device 202A and outputs information about the signal to collector module 252. Collector module 252 determines that the signal includes information about underlay flow data 204 from spine device 202A.

Similarly, virtual router module 224A of host device 210A samples, detects, senses, and/or collects underlay flow data 204 and/or overlay flow data 206 at host device 210A. Virtual router module 224A causes communication unit 215A of host device 210A to output a signal over network 205. Communication unit 245 of network analysis system 240 detects a signal from host device 210A and outputs information about the signal to collector module 252. Collector module 252 determines that the signal includes information about underlay flow data 204 and/or overlay flow data 206 from host device 210A.

Also, host device 210B may also sample, collect, sense, and/or collect underlay flow data 204. Host device 210B might not collect overlay flow data 206, however, since host device 210B may be implemented as a bare metal server not having a virtual router and/or virtual routing agent. Yet one or more of application modules 231B executing on host device 210B cause communication unit 215B to output a signal over network 205. Communication unit 245 of network analysis system 240 detects a signal from host device 210B and outputs information about the signal to collector module 252. Collector module 252 determines that the signal includes information about underlay flow data 204 from host device 210B. Host device 210N may report underlay flow data 204 to network analysis system 240 in a similar manner.

Network analysis system 240 may process both underlay flow data 204 and overlay flow data 206 received from various devices within network system 100. For instance, still continuing with the same example, collector module 252 processes the signals received from spine device 202A, host devices 210, and other devices by distributing the signals across one or more collector modules 252. In some examples, each of collector modules 252 may execute on a different physical server, and may be scaled independently and horizontally to handle the desired volume or peak capacity of flow traffic from spine devices 202, leaf devices 203, and host devices 210. Each of collector modules 252 stores each instance of underlay flow data 204 and overlay flow data 206 and makes the stored data available for ingestion in data store 259. Collector module 252 indexes the data and prepares the data for use with analytical queries. In some examples, collector module 252 correlates underlay flow data 204 reported by any host devices 210 implemented as bare metal servers by identifying virtual network identifiers associated communications involving such bare metal servers, and using such virtual network identifiers to identify, from configuration information or other overlay flow data 206 reported by other devices, virtual network name(s) associated with such communications.

Network analysis system 240 may store underlay flow data 204 and overlay flow data 206 in data store 259. For instance, in FIG. 2, collector module 252 outputs information to data store 259. Data store 259 determines that the information corresponds to underlay flow data 204 and overlay flow data 206. Data store 259 stores the data in indexed format, enabling fast aggregation queries and fast random-access data retrieval. In some examples, such underlay flow data 204 and overlay flow data 206 may be enriched, prior to storage within data store 259. Such enrichment may enable identification of virtual networks or overlay information associated with underlay flow data 204, and may enable identification of physical network devices associated with virtual networks or overlay flow data 206. In other examples, underlay flow data 204 and/or overlay flow data 206 might be stored without such enrichment, but with sufficient information to enable later identification (e.g., by flow API 256) of virtual networks or overlay information associated with underlay flow data 204, and/or to enable later identification of physical network devices associated with virtual networks or overlay flow data 206.

Network analysis system 240 may receive a query about information pertaining to a virtual network. For instance, still continuing with the same example and with reference to FIG. 2, user interface device 129 detects input and outputs, over network 205, a signal derived from the input. Communication unit 245 of network analysis system 240 detects a signal and outputs information about the signal to flow API 256. Flow API 256 determines that the signal corresponds to a query from a user of user interface device 129 for information about network devices used by a virtual network.

Network analysis system 240 may process the query. For instance, again referring to the example being described in the context of FIG. 2, flow API 256 of network analysis system 240 queries data store 259 for information about the virtual network identified in the user's query. As previously described, data store 259 may include enriched underlay flow data 204 and overlay flow data 206 that enables identification of underlay devices associated with a virtual network, and/or virtual networks associated with underlay devices.

In particular, data store 259 may include information that enables identification of bare metal servers being used in a virtual network. For example, if the virtual network being queried by the user encompasses communications between host device 210B and host device 210N, the virtual network may encompass network devices that are bare metal servers. In such an example, both host device 210B and host device 210N may report underlay flow data 204 to network analysis system 240. However, since both host device 210B and host device 210N are implemented as bare metal servers, neither host device 210B nor host device 210N may be reporting overlay flow data 206. If underlay flow data 204 and overlay flow data 206 were being reported by either host device 210B or host device 210N (or both), it would be possible to correlate underlay flow data 204 and overlay flow data 206 collected by host device 210B or host device 210N, as described in U.S. patent application Ser. No. 16/541,947, which is hereby incorporated by reference. However, if neither host device 210B nor host device 210N report overlay flow data 206, a different method, relying on just underlay flow data 204 collected by host devices 210B and 210N, may be useful to determine that both host device 210B and host device 210N are part of the queried virtual network.

In accordance with one or more aspects of the present disclosure, network analysis system 240 may determine that host device 210B and host device 210N are part of the queried virtual network by identifying any virtual network identifiers associated with bare metal servers within network system 200. For instance, underlay flow data 204 that is reported by host device 210B, host device 210N, or other devices on network 205 might not include the name of the virtual network corresponding to traffic communicated between bare metal host devices 210B and 210N. However, such underlay flow data 204 may include a reference to a virtual network identifier (i.e., a coded reference or numerical identifier) that can be used to identify, by name, any virtual network over which host device 210B and/or host device 210N are communicating. In some examples, the virtual network identifier is a number or other code that is generated internally (e.g., by SDN controller 132 and/or orchestration engine 130 of FIG. 1B). If the virtual network identifier is a code generated by SDN controller 132 or orchestration engine 130, it might not be recognizable to a user or administrator. The virtual network name, on the other hand, may be established based on input received from an administrator or user, so it may be recognizable to such an administrator or user, and may be part of a query received from user interface device 129. For at least that reason, it may be important to be able to derive the virtual network name from underlay flow data 204. In some examples, the virtual network name can be derived from the virtual network identifier based on configuration information and/or overlay flow data 206 reported by other network devices (i.e., other than host devices 210B and 210N) that have a virtual router, such as host device 210A. To derive the virtual network name from underlay flow data 204 collected by host devices 210B and 210N, flow API 256 analyzes such configuration information stored in data store 259. Flow API 256 identifies virtual network names associated with virtual network identifiers in underlay flow data 204 reported by any bare metal host devices 210, and ensures that when processing the query includes traffic between bare metal servers.

Network analysis system 240 may respond to the query. For instance, continuing with the example being described in the context of FIG. 2, flow API 256 identifies attributes specified by the query, which may include one or more likely paths of traffic associated with the queried virtual network. Flow API 256 outputs information about the determined likely paths to user interface module 254. User interface module 254 uses the information from flow API 256 to generate data sufficient to create a user interface presenting information about likely paths of traffic associate with the queried virtual network. User interface module 254 causes communication unit 215 to output a signal over network 205. User interface device 129 detects a signal over network 205 and determines that the signal includes information sufficient to generate a user interface. User interface device 129 generates a user interface (e.g., user interface 400) and presents it at a display associated with user interface device 129. In some examples, user interface 400 (e.g., such as that illustrated in FIG. 4) presents information illustrating one or more possible paths of traffic associated with the queried virtual network. User interface 400 may, in other examples, present information about fabric devices being used, present a topology view, present information about the top “N” devices processing traffic for the queried virtual network, and/or present other analytics.

Modules illustrated in FIG. 2 (e.g., virtual router modules 224, agent modules 226, application modules 231, collector module 252, user interface module 254, flow API 256, and others) and/or illustrated or described elsewhere in this disclosure may perform operations described using software, hardware, firmware, or a mixture of hardware, software, and firmware residing in and/or executing at one or more computing devices. For example, a computing device may execute one or more of such modules with multiple processors or multiple devices. A computing device may execute one or more of such modules as a virtual machine executing on underlying hardware. One or more of such modules may execute as one or more services of an operating system or computing platform. One or more of such modules may execute as one or more executable programs at an application layer of a computing platform. In other examples, functionality provided by a module could be implemented by a dedicated hardware device.

Although certain modules, data stores, components, programs, executables, data items, functional units, and/or other items included within one or more storage devices may be illustrated separately, one or more of such items could be combined and operate as a single module, component, program, executable, data item, or functional unit. For example, one or more modules or data stores may be combined or partially combined so that they operate or provide functionality as a single module. Further, one or more modules may interact with and/or operate in conjunction with one another so that, for example, one module acts as a service or an extension of another module. Also, each module, data store, component, program, executable, data item, functional unit, or other item illustrated within a storage device may include multiple components, sub-components, modules, sub-modules, data stores, and/or other components or modules or data stores not illustrated.

Further, each module, data store, component, program, executable, data item, functional unit, or other item illustrated within a storage device may be implemented in various ways. For example, each module, data store, component, program, executable, data item, functional unit, or other item illustrated within a storage device may be implemented as a downloadable or pre-installed application or “app.” In other examples, each module, data store, component, program, executable, data item, functional unit, or other item illustrated within a storage device may be implemented as part of an operating system executed on a computing device.

FIG. 3A is a conceptual diagram illustrating an example virtual network data structure associated with a virtual network as maintained by a configuration database, in accordance with one or more aspects of the present disclosure. Virtual network data structure 320 of FIG. 3A may be created (e.g., by orchestration engine 130 or SDN controller 132 of FIG. 1B) when a virtual network is established within a network (e.g., network system 100 of FIG. 1B). Virtual network data structure 320 includes a number of fields including virtual network identifier field 321 and virtual network name field 322. In the example of FIG. 3, virtual network name field 322 corresponds to the name of a virtual network associated with virtual network identifier field 321. Virtual network name field 322 may be based on administrator input (“vred-vn”), and may therefore be recognizable to an administrator or user. Virtual network identifier field 321 may be a coded reference (“18”) to virtual network name field 322 that corresponds to virtual network name field 322, and that may be included within underlay flow data 204 communicated by one or more devices 110 of FIG. 1B. In the example shown, virtual network identifier field 321 corresponds to the “vxlan_network_identifier” field of virtual network data structure 320.

FIG. 3B is a conceptual diagram illustrating an example instance of sFlow data, in accordance with one or more aspects of the present disclosure. SFlow data 330 of FIG. 3B may an instance of sFlow data reported by a bare metal server, such as host device 210B or host device 210N (see FIG. 2) or another network device. Virtual network identifier field 331 of sFlow data 330 corresponds to virtual network identifier field 321 of FIG. 3A. Accordingly, for sFlow data 330 reporting communications between two bare metal server host devices (e.g., host devices 210 in FIG. 2), sFlow data 330 is sufficient to identify virtual networks over which bare metal host devices may be communicating, if information such as virtual network data structure 320 for each virtual network is available (e.g., within data store 259 of network analysis system 240 of FIG. 2). If information such as virtual network data structure 320 is available, virtual network name field 322 can be derived from sFlow data 330 by correlating virtual network identifier field 331 of sFlow data 330 with virtual network identifier field 321 of virtual network data structure 320, and extracting from virtual network data structure 320 virtual network name field 322.

FIG. 4 is a conceptual diagram illustrating an example user interface presented by a user interface device in accordance with one or more aspects of the present disclosure. FIG. 4 illustrates user interface 400. Although user interface 400 is shown as graphical user interface, other types of interfaces may be presented in other examples, including a text-based user interface, a console or command-based user interface, a voice prompt user interface, or any other appropriate user interface. User interface 400 as illustrated in FIG. 4 may correspond to a user interface generated by user interface module 254 of network analysis system 240 and presented at user interface device 129 of FIG. 2. One or more aspects relating to the generation and/or presentation of user interface 400 may be described herein within the context of FIG. 2.

In accordance with one or more aspects of the present disclosure, network analysis system 240 may perform a query to identify a path associated with a virtual network. For instance, in an example that can be described with reference to FIG. 2, user interface device 129 detects input and outputs a signal over network 205. Communication unit 245 of network analysis system 240 detects a signal that flow API 256 determines corresponds to a query for network information. Flow API 256 performs the query (e.g., using techniques described in connection with FIG. 3A and FIG. 3B) and outputs information about the results to user interface module 254. To find the path between two virtual machines, flow API 256 may determine the most likely path (and the traffic that traveled over the determined path).

Network analysis system 240 may generate a user interface, such as user interface 400, for presentation at a display device. For instance, still referring to FIG. 2 and FIG. 4, user interface module 254 generates information underlying user interface 400 and causes communication unit 245 to output a signal over network 205. User interface device 129 detects a signal and determines that the signal includes information sufficient to present a user interface. User interface device 129 presents user interface 400 at a display device associated with user interface device 129 in the manner illustrated in FIG. 4.

In FIG. 4, user interface 400 is presented within display window 401. User interface 400 includes sidebar region 404, main display region 406, and options region 408. Sidebar region 404 provides an indication of which user interface mode is being presented within user interface 400, which in the example of FIG. 4, corresponds to a “Fabric” mode. Other modes may be available as appropriate for other network analysis scenarios. Along the top of main display region 406 is navigation interface component 427, which may also be used to select a type or mode of network analysis to be performed. Status notification display element 428 may provide information about alarms or other status information relating to one or more networks, users, elements, or resources.

Main display region 406 presents a network diagram, and may provide a topology of various network devices included within the network being analyzed. In the example shown in FIG. 4, the network is illustrated with spine devices, leaf devices, hosts, and instances, as indicated in the “Legend” shown along the bottom of main display region 406. Actual or potential data paths between the network devices and other components are illustrated within main display region 406. Although a limited number of different types of network devices and components are shown in FIG. 4, in other examples, other types of devices or components or elements could be presented and/or specifically illustrated, including core switch devices, other spine and leaf devices, physical or virtual routers, virtual machines, containers, and/or other devices, components, or elements. Further, some data paths or components of the network (e.g., instances) may be hidden or minimized within user interface 400 to facilitate illustration and/or presentation of components or data paths that are most relevant to a given network analysis.

Options region 408 provides, along the right-hand side of user interface 400, a number of input fields relating to virtual network and/or heatmap or other parameters, and relating to a selected item to be analyzed. User interface 400 accepts input through user interaction with one or more of the displayed input fields, and based on the data entered into the input fields, user interface module 254 presents responsive information about the network being analyzed.

For example, in the example of FIG. 4, user interface 400 accepts input in options region 408 about a specific timeframe (e.g., a time range) and a specific source and/or destination virtual network. Using the input that has been provided in options region 408, network analysis system 240 determines information about one or more possible data paths (e.g., the most likely data paths) through underlay network devices, which may include bare metal host devices 410B and 410N. Network analysis system 240 determines such possible data paths based on the data collected by network analysis system 240 (e.g., by collector modules 252) during a time range specified in options region 408. User interface module 254 of network analysis system 240 generates data enabling the presentation of user interface 400, where one possible data path is highlighted (by drawing each segment of the data path with a wide line) as shown in FIG. 4. In some examples, more than one data path from the source virtual network to the destination virtual network may be highlighted. Further, in some examples, one or more data paths in main display region 406 may be presented using heat map color scheme, meaning that data paths are illustrated with a color (or shade of gray) that corresponds to the amount of data being communicated over the path, or that corresponds to the extent to which the corresponding path is being utilized. Although FIG. 4 illustrates data paths using a heat map color (or gray-scale shading) scheme, in other examples, data about the utilization or traffic on data paths or through network devices can be presented in other appropriate ways (e.g., applying color to other elements of main display region 406, presenting pop-up windows, or presenting other user interface elements).

In some examples, options region 408 (or other areas of user interface 400) may include graphs or other indicators providing information about the utilization or traffic on one or more paths. In such examples, the graphs may be pertinent to, or may be generated in response to, user input entered into the input fields within options region 408.

FIG. 5 is a flow diagram illustrating operations performed by an example network analysis system in accordance with one or more aspects of the present disclosure. FIG. 5 is described herein within the context of network analysis system 240 of FIG. 2. In other examples, operations described in FIG. 5 may be performed by one or more other components, modules, systems, or devices. Further, in other examples, operations described in connection with FIG. 5 may be merged, performed in a difference sequence, omitted, or may encompass additional operations not specifically illustrated or described.

In the process illustrated in FIG. 5, and in accordance with one or more aspects of the present disclosure, network analysis system 240 may store virtual network configuration information (501). For instance, in an example that can be described with reference to FIG. 2, user interface device 129 detects input and outputs a signal over network 205. Communication unit 245 of network analysis system 240 detects a signal over network 205 and outputs information about the signal to flow API 256. Flow API 256 determines that the signal corresponds to administrator input establishing a virtual network within network system 200. Flow API 256 stores configuration information associated with the virtual network within data store 259. In some examples, the configuration information stored within data store 259 may be similar to virtual network data structure 320 of FIG. 3A.

Network analysis system 240 may collect underlay flow data 204 (502). For instance, continuing with the example being described with reference to FIG. 2, collector modules 252 of network analysis system 240 cause communication unit 245 to output one or more signals over network 205. Devices within network system 200 (e.g., host device 210B and host device 210N) detect a signal and interpret the signal as a command to enable collection of underlay flow data 204. Each of such devices, including host devices 210B and 210N thereafter may occasionally, periodically, or continually communicate underlay flow data 204 to network analysis system 240 over network 205. Collector modules 252 of network analysis system 240 receive underlay flow data 204 and store underlay flow data 204 within data store 259.

Network analysis system 240 may determine that communications identified by underlay flow data 204 took place over a specific virtual network (503). For instance, again referring to the example being described, collector module(s) 252 may receive, from communication unit 245 of network analysis system 240, information about collected data. Collector module 252 may determine that the data corresponds to underlay flow data 204 collected from one or more of host devices 210B and 210N. Collector module 252 outputs information to flow API 256. Flow API 256 analyzes the received underlay flow data 204 and uses the previously-stored configuration information (stored in data store 259) to identify a virtual network over which communications between host devices 210B and 210 took place. Flow API 256 may enrich such underlay flow data 204 with information about one or more virtual networks.

Network analysis system 240 may generate a user interface (504). For instance, once again referring to the example being described, user interface module 254 receives an indication of input corresponding to a query received from a user of user interface device 129. User interface module 254 outputs information about the query to flow API 256. Flow API 256 determines that the query corresponds to a request for information about a virtual network. Flow API 256 uses information stored within data store 259 (e.g., underlay flow data 204) to identify network devices associated with or used by the requested virtual network. Flow API 256 outputs information about its analysis to user interface module 254. User interface module 254 generates a user interface based on the information. User interface module 254 causes communication unit 245 of network analysis system 240 to output a signal over network 205. User interface device 129 detects a signal over network 205, and determines that the signal includes information sufficient to generate a user interface. User interface device 129 presents a user interface (e.g., user interface 400 of FIG. 4) responsive to the query.

For processes, apparatuses, and other examples or illustrations described herein, including in any flowcharts or flow diagrams, certain operations, acts, steps, or events included in any of the techniques described herein can be performed in a different sequence, may be added, merged, or left out altogether (e.g., not all described acts or events are necessary for the practice of the techniques). Moreover, in certain examples, operations, acts, steps, or events may be performed concurrently, e.g., through multi-threaded processing, interrupt processing, or multiple processors, rather than sequentially. Further certain operations, acts, steps, or events may be performed automatically even if not specifically identified as being performed automatically. Also, certain operations, acts, steps, or events described as being performed automatically may be alternatively not performed automatically, but rather, such operations, acts, steps, or events may be, in some examples, performed in response to input or another event.

For ease of illustration, only a limited number of devices (e.g., user interface devices 129, spine devices 202, leaf devices 203, host devices 210, network analysis system 240, as well as others) are shown within the Figures and/or in other illustrations referenced herein. However, techniques in accordance with one or more aspects of the present disclosure may be performed with many more of such systems, components, devices, modules, and/or other items, and collective references to such systems, components, devices, modules, and/or other items may represent any number of such systems, components, devices, modules, and/or other items.

The Figures included herein each illustrate at least one example implementation of an aspect of this disclosure. The scope of this disclosure is not, however, limited to such implementations. Accordingly, other example or alternative implementations of systems, methods or techniques described herein, beyond those illustrated in the Figures, may be appropriate in other instances. Such implementations may include a subset of the devices and/or components included in the Figures and/or may include additional devices and/or components not shown in the Figures.

The detailed description set forth above is intended as a description of various configurations and is not intended to represent the only configurations in which the concepts described herein may be practiced. The detailed description includes specific details for the purpose of providing a sufficient understanding of the various concepts. However, these concepts may be practiced without these specific details. In some instances, well-known structures and components are shown in block diagram form in the referenced figures in order to avoid obscuring such concepts.

Accordingly, although one or more implementations of various systems, devices, and/or components may be described with reference to specific Figures, such systems, devices, and/or components may be implemented in a number of different ways. For instance, one or more devices illustrated in the Figures herein (e.g., FIG. 1 and/or FIG. 2) as separate devices may alternatively be implemented as a single device; one or more components illustrated as separate components may alternatively be implemented as a single component. Also, in some examples, one or more devices illustrated in the Figures herein as a single device may alternatively be implemented as multiple devices; one or more components illustrated as a single component may alternatively be implemented as multiple components. Each of such multiple devices and/or components may be directly coupled via wired or wireless communication and/or remotely coupled via one or more networks. Also, one or more devices or components that may be illustrated in various Figures herein may alternatively be implemented as part of another device or component not shown in such Figures. In this and other ways, some of the functions described herein may be performed via distributed processing by two or more devices or components.

Further, certain operations, techniques, features, and/or functions may be described herein as being performed by specific components, devices, and/or modules. In other examples, such operations, techniques, features, and/or functions may be performed by different components, devices, or modules. Accordingly, some operations, techniques, features, and/or functions that may be described herein as being attributed to one or more components, devices, or modules may, in other examples, be attributed to other components, devices, and/or modules, even if not specifically described herein in such a manner.

Although specific advantages have been identified in connection with descriptions of some examples, various other examples may include some, none, or all of the enumerated advantages. Other advantages, technical or otherwise, may become apparent to one of ordinary skill in the art from the present disclosure. Further, although specific examples have been disclosed herein, aspects of this disclosure may be implemented using any number of techniques, whether currently known or not, and accordingly, the present disclosure is not limited to the examples specifically described and/or illustrated in this disclosure.

In one or more examples, the functions described may be implemented in hardware, software, firmware, or any combination thereof. If implemented in software, the functions may be stored, as one or more instructions or code, on and/or transmitted over a computer-readable medium and executed by a hardware-based processing unit. Computer-readable media may include computer-readable storage media, which corresponds to a tangible medium such as data storage media, or communication media including any medium that facilitates transfer of a computer program from one place to another (e.g., pursuant to a communication protocol). In this manner, computer-readable media generally may correspond to (1) tangible computer-readable storage media, which is non-transitory or (2) a communication medium such as a signal or carrier wave. Data storage media may be any available media that can be accessed by one or more computers or one or more processors to retrieve instructions, code and/or data structures for implementation of the techniques described in this disclosure. A computer program product may include a computer-readable medium.

By way of example, and not limitation, such computer-readable storage media can include RAM, ROM, EEPROM, CD-ROM or other optical disk storage, magnetic disk storage, or other magnetic storage devices, flash memory, or any other medium that can be used to store desired program code in the form of instructions or data structures and that can be accessed by a computer. Also, any connection is properly termed a computer-readable medium. For example, if instructions are transmitted from a website, server, or other remote source using a coaxial cable, fiber optic cable, twisted pair, digital subscriber line (DSL), or wireless technologies such as infrared, radio, and microwave, then the coaxial cable, fiber optic cable, twisted pair, DSL, or wireless technologies such as infrared, radio, and microwave are included in the definition of medium. It should be understood, however, that computer-readable storage media and data storage media do not include connections, carrier waves, signals, or other transient media, but are instead directed to non-transient, tangible storage media. Disk and disc, as used, includes compact disc (CD), laser disc, optical disc, digital versatile disc (DVD), floppy disk and Blu-ray disc, where disks usually reproduce data magnetically, while discs reproduce data optically with lasers. Combinations of the above should also be included within the scope of computer-readable media.

Instructions may be executed by one or more processors, such as one or more digital signal processors (DSPs), general purpose microprocessors, application specific integrated circuits (ASICs), field programmable logic arrays (FPGAs), or other equivalent integrated or discrete logic circuitry. Accordingly, the terms “processor” or “processing circuitry” as used herein may each refer to any of the foregoing structure or any other structure suitable for implementation of the techniques described. In addition, in some examples, the functionality described may be provided within dedicated hardware and/or software modules. Also, the techniques could be fully implemented in one or more circuits or logic elements.

The techniques of this disclosure may be implemented in a wide variety of devices or apparatuses, including a wireless handset, a mobile or non-mobile computing device, a wearable or non-wearable computing device, an integrated circuit (IC) or a set of ICs (e.g., a chip set). Various components, modules, or units are described in this disclosure to emphasize functional aspects of devices configured to perform the disclosed techniques, but do not necessarily require realization by different hardware units. Rather, as described above, various units may be combined in a hardware unit or provided by a collection of interoperating hardware units, including one or more processors as described above, in conjunction with suitable software and/or firmware. 

What is claimed is:
 1. A method comprising: storing, by a network analysis system operating within a network, configuration information that includes a name associated with a virtual network; collecting, by the network analysis system, underlay flow data associated with communications between a first server and a second server that is physically distinct from the first server; determining, by the network analysis system and based on the underlay flow data and the stored configuration information, that the first server and the second server have communicated over the virtual network; and generating, by the network analysis system, a user interface that includes information indicating that the first server and the second server have communicated over the virtual network.
 2. The method of claim 1, wherein storing the configuration information includes: storing, as part of the configuration information, a network identifier that uniquely identifies the virtual network.
 3. The method of claim 2, wherein determining that the first server and the second server have communicated over the virtual network includes: using the underlay flow data to determine, based on the network identifier stored as part of the configuration information, that the first server and the second server have communicated over the virtual network.
 4. The method of claim 3, wherein collecting underlay flow data includes: collecting sFlow data.
 5. The method of claim 4, wherein collecting sFlow data includes: collecting sFlow data that includes the network identifier but does not include the name associated with the virtual network.
 6. The method of claim 5, wherein the network identifier is a VXLAN tag.
 7. The method of claim 1, wherein storing the configuration information includes: receiving, by the network analysis system, input that includes the name associated with the virtual network; and responsive to receiving the input, storing the configuration information.
 8. The method of claim 1, wherein the first server is implemented as a bare metal server.
 9. The method of claim 8, wherein the second server is implemented as a bare metal server.
 10. The method of claim 1, wherein generating the user interface includes: receiving an indication of input requesting information about a requested virtual network, wherein the indication of input includes a name associated with the requested virtual network and a timeframe, and generating a user interface that identifies the virtual network using the name.
 11. A computing system having a storage system and processing circuitry, wherein the processing circuitry has access to the storage system and is configured to: store, within a network, configuration information that includes a name associated with a virtual network; collect underlay flow data associated with communications between a first server and a second server that is physically distinct from the first server; determine, based on the underlay flow data and the stored configuration information, that the first server and the second server have communicated over the virtual network; and generate a user interface that includes information indicating that the first server and the second server have communicated over the virtual network.
 12. The computing system of claim 11, wherein to store the configuration information, the processing circuitry is further configured to: store, as part of the configuration information, a network identifier that uniquely identifies the virtual network.
 13. The computing system of claim 12, wherein to determine that the first server and the second server have communicated over the virtual network, the processing circuitry is further configured to: use the information included within the underlay flow data to determine, based on the network identifier stored as part of the configuration information, that the first server and the second server have communicated over the virtual network.
 14. The computing system of claim 13, wherein to collect underlay flow data, the processing circuitry is further configured to: collect sFlow data.
 15. The computing system of claim 14, wherein to collect sFlow data, the processing circuitry is further configured to: collect sFlow data that includes the network identifier but does not include the name associated with the virtual network.
 16. The computing system of claim 15, wherein the network identifier is a VXLAN tag.
 17. The computing system of claim 11, wherein to store the configuration information, the processing circuitry is further configured to: receive, by the computing system, input that includes the name associated with the virtual network; and responsive to receiving the input, store the configuration information.
 18. The computing system of claim 11, wherein the first server is implemented as a bare metal server.
 19. The computing system of claim 18, wherein the second server is implemented as a bare metal server.
 20. A non-transitory computer-readable medium comprising instructions that, when executed, configure processing circuitry of a computing system to: store, within a network, configuration information that includes a name associated with a virtual network; collect underlay flow data associated with communications between a first server and a second server that is physically distinct from the first server; determine, based on the underlay flow data and the stored configuration information, that the first server and the second server have communicated over the virtual network; and generate a user interface that includes information indicating that the first server and the second server have communicated over the virtual network. 